Automatic repeating mechanism for phonographs



I L. R. McDONALD.

AUTOMATIC REPEATING MECHANISM FOR PHONOGRAPHS.

APPLICATION FILED MAR. 24, 1920. gg ggg Eatented 0015. 11, 3.921.

2 SHEETSSHEET l- L R. McDONALD.

AUTOMAHC REPEATING MECl-IANISM FOR PHONOGRAP HS.

' AFPLECATION FILED MAR. 24, 1920, Q1 fi gfig. Patented 001; M, 1921.

2 SHEETS-SHEET 2- LESLIE R. MoDONALD, 0F MONTREAL; QUEBEC, CANADA.

Specification of Letters Iatent.

lFateirted ilict 311,

Application and. search 24.. 1am. Eerial no.

To all whom it may concern:

Be it known that I, Lnsmn R. MoDoNALo, a. citizen. of the 'U-nitedStates, residing at Montreal, Province of Quebec, Dominion of Canada, have invented certain new and useful Improvements in Automatic Repeating Mechanism for Phonographs, of which the following is a specification.

My invention relates to means whereby the reproducer or sound box, carried by the tone arm of a phonograph or similar. sound reproducing device, and operating in con]un'c-' tion with a disk record, after traveling, from its initial position, inwardly across the rec- 0rd, may be automatically lifted out of contact therewith and moved back to its starting point, so as to again travelover and interpret the record. And my improvements are directed particularly to means whereby this is accomplished in a positive and accurate manner, without undue shock or Jar to the mechanism employed, and by means which can be readily attached to and disconnected from the phonograph mechanism; all as I will now more fully explain, referring in so doing to the accompanying drawings, 1n which Figure 1 is a plan view of the motor board, tone arm, sound box and turn table of a phonograph, with a disk record carried upon the turn table, and showing my repeater mechanism mounted thereupon; F g. 2 is an elevation of the same on an enlarged scale, taken on a line looking inthe direction of the arrow in Fig. 1 and at right angles to the axis of the radial arm, which is omitted for clearness, the left hand portion of the motor board, turn-table and disk being broken away, the repeater mechanism being shown in its initial position; Fig. 3 is a similarview, showing the repeater mechanism in its reproducer returning position; Fig. 4: is a vertical sectional view, on a still further enlarged scale, of the base, worm piston and dash-pot cylinder; Fig. 5 is a side view arnLFig. 6 a front View of the adjustable support for the radial return rod;

' Fig. 7 is a pers ective view of the dash-potretaining ring; ig. 8 is a detail of the top of the worm piston; Fig. 9 is a plan view of the worm engaging member carried by the radial return rod; F i 10 is a plan view of a section of they radial return rod and of the inner stop carried thereby; and Fig. 11 is a view of the same, looking tothe left on line 11-11 of Fig. 10.

ig. 3, projects through the center of the record disk 3, in the usual manner. And over this spindle, and resting on the record,

I place a base '2', carrying a worm piston 8,

the lower end of which is rovidedwith a spindle gripping device, which I have illustratedas consisting of a sleeve 9, screwed into the lower part 'of the worm piston, and

split so as to permit its parts to yieldablv embrace and grip the spindle. The thread 10in the worm piston is ioreferablv an acute trapezoidal thread. And, in practice, I have found that a face angle of about degrees, and a pitch of'from .15 130 20 gives satisfactory results. The upper end of, the thread gradually merges into the surface of the worm piston, as shown at 10 in Fig. 8.

The upper end of the worm cylinder is slightly enlarged, as at 11, and, preferably, terminates in an under-cut boss 12, around which is slipped a thin flexible washer 13.

A retaining ring 14.- is ada ted-to slide upon the body of the worm cy inder, but is prevented by the enlargement 11 from escaping over its top.

so I

A dash-pot cylinder, 15, slides over the worm iston 8, and is provided" at its lower end with an annular-enlargementOG into' which the retaining ring 14.- fits snugly; so

that, when the ring and the cylinder-have been assembled around the worm piston, the dash-pot cylinder -maynot be drawn enes tirely up off the worm cylinder without the use of force-sufficient to separate it from the retaining ring 14.v i

The dash-pot cylinder 15 is provided near its bottom with a recess or slot 16 on each side, and with an opening 17 between the slots 16, which slots slidably receive the arms ice] 18, 18 of the forked member 19, which is also provided with a downwardly bent prong sliding movement being suilicient to allow the prong to be pushed into or withdrawn from the'groove 10 in the worm cylinder.

The forked member 19 is rigidly secured to one end of a rod 21, the main portion of which is bent upon .a true curve coinciding with the sweep of the sound box when moving with the radial tone arm; the outer endprovided with a flange 29 adjusted to bear against and slidably grip the rod 21, which is milled flat on its under side to prevent the stop from turning on it. By pinching the arms of the stop together its grip on the rod will be relaxed. and it can he slid back and forth as desired.

The inner stop 30 embodies meanswhereby it is slidably and yieldably mounted upon the rod These means are shown as consisting of two arms 31 and 32, carrymg flanges 33 and 34: pierced to receive the rod 21, the opening in the flange 34: being elongated so as to allow the flange to play slightly to and fro on the rod. Anotherarm 35 presses against the flattened under-- side of the rod, so as to resist the turning of the stop around the rod.

A coiled spring 36 fits snugly around the rod, its end 37 being hooked over the flange 34 so as to normally draw that end of the flange in toward the rod as far as its elongated opening will permit; thus throwing the free end of the stop 30 slightly forward and holding it yieldably in that position. The end of the stop is preferably covered with a sound deadening and shock absorbing element, as 38, which may be of rubber or similar material.

The repeater mechanism maybe assembled upon a phonograph machine by putting a disk record in place and then pressing the base 7 with'the dash-pot cylinder and rod 21 attached to it down over the spindle O of the shaft 6, which it will grasp so as to be rotated therewith.

The guide 23 havingbeen secured to" the motor board, the outer end of the rod will,

slide therethrough, and may be adjusted to a suitable height by means of the sliding support 24.

Care should be taken in adjusting the rod 21 to see'that the curve of the rod coincides with the arc traversed by the sound box, and also that in its initial position the rod lies substantially parallel with the face of the record.

. iseaaae To adjust the mechanism to the particular record to be repeated, place the needle in the reproduce! and tip down the reproducer with the needle in the outside groove, then gently press the radial arm outward so ,as to take up the slack or end play of the rod, and at the same time gently slide the outside stop inward until it just comes in contact with the reproducer. 7

Next, lift up the reproducer and move it inward, setting the needle in the inside or finishing groove of the record; after which gently press outward the inside actuating stop until the same comes in contact with the needle. records are more or less eccentric, it is better to make this adjustment with the needle set five or six grooves from the last or inside groove.

Owing to the fact that most-- ing with it the radial rod 21, causing the 7 prong 20 on the member 19 to come in contact with the worm piston 8. At this point the spring 36 performs an important function. For the reproducer' or sound-box, moving slowly inward, because of eccentricities on the record, seldom proceeds at a uniform rate. And if it was pressed positively and unyieldably against the surface of the worm piston and its progress arrested thereby, the needle would be forced to ride out of its groove in the record as it continued to revolve. However, the flexibility of the stop 30 allows the needle to push the stop ahead of it, until the-revolution of the worm piston brings the worm groove around to the prong 20, which will then enter the groove, and be carried upwar 'd, as the worm piston continues to revolve, lifting with it the dash pot cylinder and the end of the rod 21.

' When the rod has been raised a little distance it will pick up the sound box and will carry it upward until the inclination of the rod is such that the weight of. the soundbox will cause it to slide down' along the rod, and come against the outer stop 26, the impact of the sound box against the stop 26 causng the rod 21 to slide outward, withdrawmg the prong 20 from the worm groove 10 and allowing the dash-pot cylinder to slide gently down the worm iston, as the air gradually escapes from wlthin the cylinder, untll the rod '21 has reached its initial position, when the needle will have again entered the roove in the record, and the repetition of t e record will again take place.

- bodying If the prong 20 is not withdrawn from the groove by the sound box striking the stop v26, it will be automatically disen gaged therefrom when it reaches the end of the groove,the merging of the groove into the surface of .the cylinder having the the groove 10 as the arm falls to a horizontal position.

By means of my improvements I secure .a simple and efiicient, device, which may be quickly and conveniently attached to and removed from a phonograph, and which will'raise the reproducer away from the record disk and return it to its initial position and place it again in the groove of the record, without undue shock or noise or jar to any part of the apparatus.

Itis obvious that'details of construction may be varied, by the use of mechan cal equivalents, or the like, without departing from the s irit of m invention asclaimed'.

Having t us descri ed my invention, what I claim and desire to secure by Letters Patentof the United States is 1. The combination, in a sound repro-' ducing instrument embodying a rotatable vided with a sound'box and a record fol owin needle, ofautomatic means for raising the sound box from the recordto permit the sound box to swing outward, and pneumatically checked means, centrally disposed relative to the rotatable record support, for retarding the return descent of such raising means.

- 2. The combination, in a sound reproducing instrument embodying a rotatable record support. and a movable tone-arm with a sound box and a record ollowing needle, of automatic means for raising the sound box from the record to permit the sound box to swing outward, and pneumatically checked means, centrally disposed. relative to the rotatable record support, and ema dash-pot cylinder in combination with the raising means, for retarding the return descent of 'such raising means.

3. The combination, in a sound reproducing instrument embodying a rotatable record support and a movable tone-arm pro- 'vided with a sound box and a record following needle, of automatic means, embodythe sound box from t e record topermit the soundbox to swing outward, and pneumatically checked means, centrally disposed rovided relative to the rotatable record support and embodying a rotatable worm piston and a dashof. cylinder .mounted thereupon, for retar mg t e return descent of such raising means.

4. The combination, in a sound reproducing instrument embodying a rotatable record support and a movable tone-arm with a sound box and a record ollowing needle, of automatlcmeans for raising the sound box. from the record to permit the.

sound box to swing outward, embodying a rotatableworm piston, a dash-pot cylinder mounted thereupon, and a longitudinally 'movablesound-box supporting-rod adapted to be raised by said 'worm piston'and to be.

delayed in its return descent by such dashpot cylinder. -.5. he combination, in a sound reproducing instrument embodying a rotatable record support and a movable tone-arm rovided needle, of automatic means for raising the rovidedsound box from the record to permit the to be delayed in its return descent by such dash-pot cylinder. I

v6. The comb'nation, in a sound reproducing instrument embodying a rotatable record support and a movable tone-arm provided with a sound box anda record following needle, of a longitudinally movable, soundbox supportin -rod and a vertically adjustable support or the outer end of said rod, adapted to permit longitudinal movement of the rod in relation thereto.

7. The combination, inasound reproducing instrument'embodying a'rotatable record support, movable tone-arm, sound box and needle, of a slidable and inclinable tone-arm supporting-rod provided with an inside stop adapted to intercept the movement of the sound box and to thereby slide the supporting-rod bodily in one direction, and also provided with an outside tone-arm stop, adapt- 8. The combination, in a sound reproducing1 instrument embodying a rotatable recor support, movable tone-arm, sound box and needle, of a slideable and inclineable tone-arm supporting-rod provided with a yieldable inside stop adapted to intercept the'movement of the tone-arm and to thereby 'slide the supporting-rod bodily in one direction, and also provided with a ieldable outside stop,'a dapted to intercept t e -move-' I 85 with a sound boxand a record ollowing I 1 neeaaae ment of the sound box and tg thereby slide the supporting-rod bodily in the other direction.

ing instrument embodying a rotatable record support and a movable tone-arm provided with a sound box and a record tollowing needle, of automatic means embodying engaging the worm of said piston, means actuated by the movement of the sound box lowing needle, of automatic means embody- .a rotatable piston, provided with aiworm for causing such engagement, and means similarly actuated for terminating the engagement.

10. The combination, in a. sound repro ducin instrument embodying a rotatable recor 7 support and amovable tonearm provided with a-sound box and a record foling a rotatable piston,provided with a worm having a downwardly and'inwardly inclined upper face, sound-box supporting-rod guiding means, a sound-box supporting-rod provided with holding means, consisting of a deflected element, for detachably engaging the worm of said piston, means actuated by the movement of the sound box for causing such engagement, and means similarly actuated for terminating the engagement;

11. The combination, in a sound reproducing instrument embodying a rotatable record support and a movable tone-arm provided with a sound box and a record following needle, of automatic means embodying a rotatable piston, provided with a worm, .and a dash-pot cylinder provided with an opening therethrough and with rod guiding means and mounted on the piston, a sound-boxsupporting-rod provided with elements cotiperating with said rod guiding means and with holding means, consisting of a deflected element, passin through said opening in the dash-pot cylin er,- fordetachably engaging the worm of said piston, -means actuated b the movement of the sound box for causing such engagement, and

9. The combination, in a sound reproduc means similarly actuated for terminating the engagement.-

12. The combination, in a sound reproduc ing. instrument embodyin a rotatable record support and a mova le tone arm provided with a sound box and a record following needle, of automatic means embodying a rotatable piston, provided with a worm having an inwardly and downwardly disposed depression in its upper face, soundbox' supporting-rod guiding means detachably mounted thereupon a sound-box suporting-rod provided with holding means or detachably engaging the worm of said piston, means actuated by the movement of the sound box for causing suchengagement,

and'nieans similarly actuated for terminating theengagement.

13; The combination, in a sound repro- (inch? instrument embodyin ,ajrotatable recor support and a movable tone-arin provided with a sound box and a record following needle, of automatic means embody-1 ing a rotatable piston, provided with a worm, supporting-rod guiding means,'embodying a dash-pot c linder, associated with the piston, a soundor supporting-rod, in slidable relation to the dash-pot cylinder, provided with holdin means for 'detachably engaging the worm 0 said piston, means actuated by the movement of the sound box for causing such engagement, and a plurality of means for terminating such engagement. 14:. The combination, in a sound reproducing instrument embodying a rotatable record support and a movable tone-arm provided with a sound box and a record following needle, of automatic-Ineansembodying a rotatable piston, provided with a worm having a raised marginal element upon its-upper edge, supporting-rod guiding means associated with the piston, a soundbox sup-- porting-rod providedwith holding means for detachably engaging the wormof said piston, means actuated by the movement of the sound box for causing such engagement, and a plurality of means for terminating such engagement.

LESLIE R. MCDONALD. 

